Spinel-Structured High Entropy Oxides: Low Temperature Synthesis, Characterization, and Potential Applications
High entropy oxides (HEOs) have recently attracted increasing attention due to their remarkable properties and relatively low cost. Herein we report a simple, highly scalable, and low temperature method for synthesizing spinel (FeNiCoCuZn)<sub>3</sub>O<sub>4</sub> (HEO). We heated an aqueous solution containing divalent cations in high alkali environments to temperatures of 25 - 95 °C for 24 h under atmospheric pressure. The HEO, synthesized at 95 °C for 24 h in 1 M KOH, was paramagnetic at room temperature, with a magnetic mass susceptibility of χ = (7.5 ± 0.2) × 10<sup>-7</sup> m<sup>3</sup>·kg<sup>-1</sup>. It demonstrated stable electrochemical lithium storage performance, with a gravimetric capacity of ∼300 mAh·g<sup>-1</sup> at 100 mA·g<sup>-</sup> <sup>1</sup>. It was also active in the electrocatalytic oxygen evolution reaction with an overpotential of 460 mV in alkaline media. The band gap energies were in the range of 2.4 eV. Our advancement in the synthesis and processing of transition metal-based HEOs will undoubtedly render them a viable solution for next generation materials for energy production and storage.
Authors
- Lyubov V. Titova (ORCID: https://orcid.org/0000-0002-2146-9102)
- Michel W. Barsoum (ORCID: https://orcid.org/0000-0001-7800-3517)
- Kaustubh Sudhakar (ORCID: https://orcid.org/0009-0007-1807-2861)
- İrem Burcu Algan Şimşek (ORCID: https://orcid.org/0000-0001-5206-3722)
- Ulf Wiedwald (ORCID: https://orcid.org/0000-0002-3209-4078)
- Vibha Kalra (ORCID: https://orcid.org/0000-0002-2630-1560)
- Hussein O. Badr (ORCID: https://orcid.org/0000-0002-6355-3978)
- Gregory R. Schwenk (ORCID: https://orcid.org/0000-0003-1075-7894)
- Neal Amadeus Cardoza (ORCID: https://orcid.org/0000-0001-9380-390X)
- Erika Colin‐Ulloa (ORCID: https://orcid.org/0000-0002-2697-4458)
- Michael Farle (ORCID: https://orcid.org/0000-0002-1864-3261)
- Mohamed Abdelfattah Ibrahim (ORCID: https://orcid.org/0009-0009-7791-3610)
Institutions
- Worcester Polytechnic Institute (US)
- Cornell University (US)
- Smith Institute (GB)
- University of Duisburg-Essen (DE)
- Drexel University (US)
- Gazi University (TR)
Publication Details
- Journal
- ACS Omega
- Published
- 2025-08-25
- DOI
- https://doi.org/10.1021/acsomega.5c00902
- Citations
- 3
- Primary Topic
- Magnetic and transport properties of perovskites and related materials
- Type
- article
- Field-Weighted Citation Impact
- 1.28
Funders
- U.S. Department of Energy
- Drexel University
- Deutsche Forschungsgemeinschaft
- Türkiye Bilimsel ve Teknolojik Araştırma Kurumu
- Office of Science
- Oak Ridge Institute for Science and Education
- Workforce Development for Teachers and Scientists
- Brookhaven National Laboratory